TomR wrote:

What if, instead of a sink, I had a big funnel that was attached to a
15 foot garden hose. And, I put the other end of the garden hose
into a 4-inch cast iron pipe. If I pour water into the funnel (the
substitute sink), I assume that the water will just flow into the
funnel, through the hose, and into the 4-inch cast iron pipe. I
would not assume that the water going down would go "glub-glub" since
the top of the funnel is open. I would assume tha the water just
goes down on its own and there would be nothing holding it back
because the funnel is open.

There is also no air in the hose to be displaced.